Keypad having three-dimensional patterns

ABSTRACT

A keypad having three-dimensional patterns includes a base layer, a light-guiding plate, a pattern layer, a shielding layer and a keycap layer. The light-guiding plate is overlapped on the base layer. The pattern layer is provided on the light-guiding plate. A plurality of three-dimensional patterns is provided on the front surface of the pattern layer. The shielding layer is coated on the back surface of the pattern layer, and is formed with a plurality of hollowed regions to correspond to the three-dimensional patterns. The keycap layer is overlapped on the pattern layer and formed with a plurality of keycaps to correspond to the three-dimensional patterns.

RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 12/060,545, filed on Apr. 1, 2008.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a keypad, and in particular to a keypadhaving three-dimensional patterns.

2. Description of Prior Art

With the progress and development of technology, modern consumersrequest electronic products such as mobile phone, personal digitalassistant (PDA), ultra mobile personal computer (UMPC) to be designed ina more personalized and delicate manner. However, these electronicproducts can be only operated via keypad so as to transmit signals froma user to the electronic products or vice versa. Moreover, the userrequests the keypad of the electronic product to be varied continuously.Therefore, it is an important issue for the manufacturers of keypad todevelop keypad of more competitiveness to satisfy the request of modernpeople.

Japanese Patent Publication No. 2000-340059 discloses a conventionalkeypad and a method for manufacturing the same. As shown in FIG. 1, thekeypad includes a base layer 10 a, a pattern layer 12 a, a keycap layer14 a and a colored light-transmitting film 17 a. The front surface ofthe pattern layer 12 a is provided with three-dimensional patterns 121a. The keycap layer 14 a is provided with troughs to correspond to thethree-dimensional patterns 121 a and the keycap layer 14 a is overlappedon the front surface of the pattern layer 12 a. The back surface of thepattern layer 12 a is printed with the colored light-transmitting film17 a. The base layer 10 a is adhered to the underside of thelight-transmitting film 17 a. With the above arrangement, a keypad canbe achieved. Further, the method for manufacturing the keypad includes astep of overlapping a pattern layer and a keycap layer. First, a bottomplate and three-dimensional patterns are integrally formed. Thethree-dimensional patterns protrude from the top surface of the bottomplate. Next, the top surface of the three-dimensional pattern isprinted. Then, the three-dimensional patterns of the bottom plate areembedded in the keycap layer via a hot welding process.

Further, Japanese Patent publication No. 2000-331554 discloses anotherkind of keypad and a method for manufacturing the same. According tothis method for manufacturing the keypad, cavities havingthree-dimensional patterns are formed in an inner surface of a keycaplayer. The inner surface of the keycap layer is printed with alight-shielding film. Then, the inner surface of the cavity havingthree-dimensional patterns is coated with a light-transmitting coloredfilm. In this way, the method for manufacturing keypad can be completed.

Although the above-mentioned keypad and the method for manufacturing thesame can obtain keypads having three-dimensional patterns, PatentPublication No. 2000-340059 only teaches a step of printing on the topsurface of the three-dimensional patterns. Therefore, the whole shape ofthe three-dimensional pattern cannot be displayed sufficiently, and thusthe recognition and aesthetic feeling thereof are not good. Further,since both the above-mentioned patent publications do not provide alight-guiding plate, the illuminated area is relatively small and thusit can be only applied to a relative small keypad or single keypad.Therefore, for a keypad having a large operating area, the conventionalkeypad cannot satisfy this requirement for use.

Further, China Patent Publication No. CN2544299Y discloses anotherkeypad assembly, which includes a keypad layer, a first pattern layer, arefracting layer and a second pattern layer. The keypad layer is alight-transmitting body. The first pattern layer is an opaque body thatis overlapped with the keypad layer. The first pattern layer is providedwith first patterns formed by hollowed portions. The refracting layer isa translucent body that is located below the keypad layer and the firstpattern layer. The underside of the refracting layer is formed with aback surface. The second pattern layer is an opaque body that isattached to the back surface of the refracting layer. The second patternlayer is provided with second patterns formed by hollowed portions. Thelight emitted by light-emitting elements is projected toward the keypadlayer from the underside of the second pattern layer, so that the firstand second patterns can be displayed on the keypad layer, therebyachieving a multiple displaying effect. Although the above-mentionedkeypad assembly has a multiple displaying effect, it relies on the factthat the first and second patterns are formed on the first and secondpattern layers respectively. As a result, the total thickness of thekeypad would be large and thus increasing the weight thereof. Therefore,it is not suitable for the electronic products that tend to be producedtoward more and more compact. Further, the light-emitting element isformed underneath the second pattern layer, increasing the total height.As a result, the thickness of the electronic product cannot be reducedsufficiently. Moreover, the refracting layer is a translucent body, sothat the recognition and aesthetic feeling of the displayed secondpattern are not good.

SUMMARY OF THE INVENTION

The present invention is to provide a keypad having three-dimensionalpatterns and a method for manufacturing the same. With the abovearrangement, patterns such as characters, symbols or icons can bedisplayed in the keycaps in a three-dimensional manner, therebyincreasing the recognition and aesthetic feeling.

The present invention provides a keypad having three-dimensionalpatterns, which includes a base layer, a light-guiding plate, a patternlayer, a shielding layer and a keycap layer. The light-guiding plate isoverlapped on the base layer. The pattern layer is provided on thelight-guiding plate. A plurality of three-dimensional patterns isprovided on the front surface of the pattern layer. The shielding layeris coated on the back surface of the pattern layer, and is formed with aplurality of hollowed regions to correspond to the three-dimensionalpatterns. The keycap layer is overlapped on the pattern layer. Thekeycap layer is formed with a plurality of keycaps to correspond to thethree-dimensional patterns.

The present invention provides a method for manufacturing keypad havingthree-dimensional patterns, which includes the steps of:

-   -   a) preparing a first mold, and filling a first ultra-violet        curable resin in the first mold;    -   b) disposing a shaping layer in the first mold, and overlapping        the shaping layer on the first ultra-violet curable resin;    -   c) irradiating the first ultra-violet curable resin with an        ultra-violet lamp to cure the resin to form a pattern layer,        forming a plurality of three-dimensional patterns on a front        surface of the pattern layer;    -   d) preparing a second mold, and filling a second ultra-violet        resin into the second mold;    -   e) disposing the assembled structure formed in the step c) in        the second mold and overlapping it on the second ultra-violet        curable resin;    -   f) irradiating the second ultra-violet curable resin with the        ultra-violet lamp to cure the resin to form a keycap layer, and        forming a plurality of keycaps on a front surface of the keycap        layer; and    -   g) printing a shielding layer on a back surface of the shaping        layer, and forming a plurality of hollowed regions beneath the        three-dimensional patterns.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an assembled cross-sectional view showing a conventionalkeypad assembly;

FIG. 2 is a flow chart showing the method for manufacturing keypad ofthe present invention;

FIG. 3 is an exploded perspective view showing a first mold and theshaping layer of the present invention;

FIG. 4 is a cross-sectional view showing the pattern layer of thepresent invention being irradiated with a ultra-violet lamp;

FIG. 5 is a schematic view showing the external appearance of theassembled structure having the pattern layer and the shaping layer ofthe present invention;

FIG. 6 is an exploded perspective view showing a second mold and theassembled structure of the present invention;

FIG. 7 is a cross-sectional view showing the keycap layer of the presentinvention being irradiated with a ultra-violet lamp;

FIG. 8 is a schematic view showing the external appearance of the keypadafter finishing the step g) of the method of the present invention;

FIG. 9 is an assembled cross-sectional view showing the assembledstructure of FIG. 8 and a shielding layer;

FIG. 10 is a schematic view showing the external appearance of the backsurface of the assembled structure in FIG. 9.

FIG. 11 is an exploded perspective view showing the assembled structureof FIG. 10 and a light-guiding plate;

FIG. 12 is an assembled cross-sectional view showing the assembledstructure of FIG. 10 and a light-guiding plate;

FIG. 13 is an assembled cross-sectional view showing the assembledstructure of FIG. 12 and a base layer;

FIG. 14 is an assembled view showing the keypad of the present inventionbeing used in a mobile phone;

FIG. 15 is a schematic view showing the arrangement of the keypad ofFIG. 14 and light-emitting elements;

FIG. 16 is an assembled cross-sectional view showing the state beforethe action of the keypad of FIG. 15 and the circuit board;

FIG. 17 is an assembled cross-sectional view showing the state after theaction of the keypad of FIG. 15 and the circuit board;

FIG. 18 is an assembled schematic view showing the keypad of the presentinvention being used in a PDA;

FIG. 19 is an assembled schematic view showing the keypad of the presentinvention being used in an automobile stereo panel; and

FIG. 20 is an assembled schematic view showing the keypad of the presentinvention being used in an UMPC.

DETAILED DESCRIPTION OF THE INVENTION

The detailed description and technical contents of the present inventionwill be explained with reference to the accompanying drawings. However,the drawings are illustrative only, but not used to limit the scope ofthe present invention.

The keypad having three-dimensional patterns manufactured by the presentinvention includes a base layer 10, a light-guiding plate 11, a patternlayer 12, a shielding layer 13, a keycap layer 14, and a shaping layer15, as shown in FIG. 13.

Please refer to FIGS. 2 to 8. The present invention provides a keypadhaving three-dimensional patterns and a method for manufacturing thesame. The method includes the steps as follows.

a) A first mold 3 is prepared, and a first ultra-violet curable resin infilled the first mold 3 (FIG. 3). In this step, the first mold 3 has arectangular block 31 made of a light-transmitting material. The top ofthe block 31 is provided with a recess 32. The inner surface of therecess 32 is provided with a plurality of pattern cavities 33 such ascharacters, symbols, icons or the like. In the present embodiment, thepattern cavity 33 includes any of “0˜9”, “*”, “#”, “OK” etc., but it isnot limited thereto. In manufacturing, the first ultra-violet curableresin (not shown) is filled uniformly into the recess 32 and eachthree-dimensional pattern cavity 33. Then, the resin is leveled by meansof a pressing plate or roller (not shown).

b) A shaping layer 15 is disposed in the first mold 3, and is overlappedon the first ultra-violet curable resin as shown in FIG. 3. In thisstep, the shaping layer 15 can be made of any one of PET, PC or themixture of PMMA and PC. In manufacturing, the shaping layer 15 isoverlapped on the upper surface of the first ultra-violet curable resinat a position corresponding to the recess 32.

c) The first ultra-violet curable resin is irradiated with aultra-violet lamp 4, so that the resin is cured to form a pattern layer12. A plurality of three-dimensional patterns 121 is formed on a frontsurface of the pattern layer 12, as shown in FIG. 4. In this step, sincethe block 31 has a light-transmitting property, the underside of theblock 31 can be irradiated with ultra-violet light by using theultra-violet lamp 4. In this way, the first ultra-violet curable resinis cured to form a pattern layer 12, and the pattern layer 12 can be anyone of a light-transmitting body or a translucent body. A plurality ofcorresponding three-dimensional patterns 121 is formed in the patterncavities 33 respectively. The three-dimensional patterns 121 can be anyone of characters, symbols, icons or the combination thereof. FIG. 5 isa perspective view showing the front surface of an assembled structurehaving the shaping layer 15 and the pattern layer 12 after being removedfrom the first mold 3. In addition, the inner surfaces of the recess 32and the pattern cavities 33 mentioned in the step a) can be processed bymeans of sand blasting, so that the front surface of the pattern layer12 can form a rough surface (not shown), thereby enhancing thebrightness of the three-dimensional patterns 121, and increasing thestrength of the combination of the pattern layer 12 with the keycaplayer 14.

d) A second mold 5 is prepared. A second ultra-violet curable resin isfilled into the second mold 5 (FIG. 6). In this step, the second mold 5has a rectangular block 51 made of a light-transmitting material. Thetop of the block is provided with a recess 52. The inner surface of therecess 52 is provided with a plurality of keycap cavities 53. Inmanufacturing, the second ultra-violet curable resin is filled uniformlyinto the recess 52 and each keycap cavity 53. Then, the resin is leveledby means of a pressing plate or roller (not shown).

e) The assembled structure formed in the step c) is disposed in thesecond mold 5, and is overlapped on the first ultra-violet curable resin(FIG. 7). In this step, the assembled structure having the shaping layer15 and the pattern layer 12 is overlapped on the upper surface of thesecond ultra-violet curable resin. In this way, each three-dimensionalpattern 121 is located at a position corresponding to each keycap cavity53, and each three-dimensional pattern 121 is embedded in the secondultra-violet curable resin.

f) The second ultra-violet curable resin is irradiated with theultra-violet lamp 4, so that the resin is cured to form a keycap layer14. A plurality of keycaps 141 is formed on a front surface of thekeycap layer 14 as shown in FIGS. 7 and 8. In this step, since the block51 has a light-transmitting property, the underside of the block 51 isirradiated with the ultra-violet light generated by the ultra-violetlamp 4, so that the second ultra-violet curable resin can be cured toform a keycap layer 14. A plurality of keycap 141 is formed on the frontsurface of the keycap layer 14, and each three-dimensional pattern 121is formed in each keycap 141. FIG. 8 is a perspective view showing thefront surface of the keypad that is completely cured and removed fromthe second mold 5.

g) A shielding layer 13 is printed on a back surface of the shapinglayer 15. A plurality of hollowed regions 131 is formed beneath thethree-dimensional patterns 121 (FIGS. 9 and 10). In this step, a die(not shown) having the three-dimensional patterns 121 is prepared first.Then, the die is attached to the back surface of the shaping layer 15.The shielding layer 13 such as inks is printed and coated on the backsurface of the shaping layer 15. Finally, the die is removed from theback surface of the shaping layer 15, thereby forming a plurality ofhollowed regions 131 exactly beneath the three-dimensional patterns 121.Via the above steps, the manufacturing of keypad of the presentinvention can be completed. The shielding layer 13 can be also printedand coated on the back surface (not shown) of the pattern layer 12.Further, a plurality of hollowed portions 131 is formed underneath thethree-dimensional patterns 121.

Further, the present invention includes a step h) of overlapping alight-guiding plate 11 on the back surface of the shielding layer 13(FIGS. 11 and 12). In this step, the light-guiding plate 11 is formedwith a plurality of light-guiding microstructures 111 exactly beneatheach keycap 141 and each three-dimensional pattern 121. The light isrefracted by the light-guiding structures and emitted from the upside ofthe light-guiding plate 11. Further, one side of the light-guiding plate11 is provided with two notches 112. The inner surfaces of the twonotches 112 are formed with tooth-like stripes 113. In addition, abinding layer 16 (FIG. 12) is connected between the light-guiding plate11 and the shaping layer 15. The binding layer 16 may be acrylic glueand is applied to the positions avoiding the light-guidingmicrostructures 111.

Further, the present invention includes a step i) of connecting a baselayer 10 to the back surface of the light-guiding plate 11 by pressing(FIG. 13). In this step, the base layer 10 may be made of silicone,which is connected with the underside of the light-guiding plate 11 bymeans of adhesion. Alternatively, after the light-guiding plate 11 andthe base layer 10 are connected with each other by means of a hotpressing process, the light-guiding plate 11 is adhered to the undersideof the shaping layer 15 via the binding layer 16. Further, the lowersurface of the base layer 10 is formed with bumps 101 each of which islocated exactly beneath the corresponding keycap 141. Via thisarrangement, the keypad of another embodiment of the present inventioncan be completed.

Please refer to FIGS. 14 to 17. FIG. 14 is an assembled view showing thekeypad of the present invention being used in a mobile phone. FIG. 15 isa schematic view showing the arrangement of the keypad of FIG. 14 andlight-emitting elements. FIG. 16 is an assembled cross-sectional viewshowing the state before the action of the keypad of FIG. 15 and acircuit board. FIG. 17 is an assembled cross-sectional view showing thestate after the action of the keypad of FIG. 15 and the circuit board.The keypad of the present invention can be used in a mobile phone 600.Light-emitting elements 601 (FIG. 15) and a circuit board 602 (FIG. 16)are arranged on the mobile phone 600. The two notches 112 of thelight-guiding plate 11 are arranged to correspond to the light-emittingelements 601. The tooth-like stripes 113 are used to increase the ratioand uniformity of the light of the light-emitting elements 601 enteredthe light-guiding plate 11. In use, pressing the keycap 141 can contacta conductive terminal of the circuit board 602 via the bump 101 of thebase layer 10, thereby generating a corresponding trigger signal.

Please refer to FIGS. 18 to 20. FIG. 18 is an assembled schematic viewshowing the keypad of the present invention being used in a PDA. FIG. 19is an assembled schematic view showing the keypad of the presentinvention being used in an automobile stereo panel. FIG. 20 is anassembled schematic view showing the keypad of the present inventionbeing used in a UMPC. In addition to the mobile phone 600, the presentinvention can be also used in the keypad of a personal digital assistant(PDA) 700 as shown in FIG. 18, an automobile stereo panel 800 as shownin FIG. 19, or an ultra mobile personal computer (UMPC) 900 as shown inFIG. 20.

According to the above, the present invention really has industrialapplicability, novelty and inventive steps, and has not been seen inproducts of the same kind or let used in public. Therefore, the presentinvention conforms to the requirements for an invention patent.

Although the present invention has been described with reference to theforegoing preferred embodiments, it will be understood that theinvention is not limited to the details thereof. Various equivalentvariations and modifications can still occur to those skilled in thisart in view of the teachings of the present invention. Thus, all suchvariations and equivalent modifications are also embraced within thescope of the invention as defined in the appended claims.

1. A keypad having three-dimensional patterns, comprising: a base layer;a light-guiding plate overlapped on the base layer; a pattern layerprovided on the light-guiding plate, a plurality of three-dimensionalpatterns being provided on a front surface of the pattern layer; ashielding layer coated on a back surface of the pattern layer and formedwith a plurality of hollowed regions to correspond to thethree-dimensional patterns; and a keycap layer overlapped on the patternlayer, the keycap layer being formed with a plurality of keycaps tocorrespond to the three-dimensional patterns.
 2. The keypad havingthree-dimensional patterns according to claim 1, wherein the patternlayer is a light-transmitting body or a translucent body.
 3. The keypadhaving three-dimensional patterns according to claim 1, wherein thethree-dimensional pattern is any one of characters, symbols, icons orthe combination thereof.
 4. The keypad having three-dimensional patternsaccording to claim 1, wherein the front surface of the pattern layer isa rough surface.
 5. The keypad having three-dimensional patternsaccording to claim 1, wherein the light-guiding plate is formed with aplurality of light-guiding microstructures to correspond to theundersides of the keycaps and the three-dimensional patterns.
 6. Thekeypad having three-dimensional patterns according to claim 1, whereinone side of the light-guiding plate is provided with a notch, and aninner surface of the notch is formed with a tooth-like stripe.
 7. Thekeypad having three-dimensional patterns according to claim 1, furthercomprising a shaping layer located between the pattern layer and thelight-guiding plate.
 8. The keypad having three-dimensional patternsaccording to claim 7, further comprising a binding layer located betweenthe light-guiding plate and the shaping layer.
 9. The keypad havingthree-dimensional patterns according to claim 1, wherein a plurality ofbumps are formed on one surface of the base layer away from thelight-guiding plate to correspond to the keycaps.